Workshop 2
Extracting high-resolution amplitude information: “migration plus inversion” or “full-waveform inversion”?
Sunday, June 1st |
Convenors
- Simon Baldock (TGS)
- Lorenzo Casasanta (Shearwater)
- James Cooper (Viridien)
- James McLeman (DUG)
- Andrew Ratcliffe (Viridien)
- James Rickett (SLB)
Description
The conventional approach to extracting amplitude information from P-wave seismic data has been the long established “migration plus inversion”. Here the integrity of the migration algorithm to preserve the amplitudes in the pre-stack PP migrated gathers is a key aspect and has been the motivation for substantial theoretical developments in the decades since the initial groundbreaking work on imaging.
Recent advances in full-waveform inversion (FWI) have expanded into preserving and extracting amplitude information from pre-stack data in a similar manner, where analysis of the amplitude versus angle (AVA) from an FWI-derived reflectivity gives access to information about Vp, Vs and density. Yet this is in contrast to FWI’s ultimate goal of (elastically) inverting full-bandwidth versions of these models, which would make pre-stack AVA analysis redundant. This poses the tricky question as to what value FWI’s pre stack AVA might bring over full-bandwidth elastic updates? Is it simply an efficiency issue, with acoustic-based FWI approaches being much more affordable than elastic-based ones for high-resolution updates? Or is it driven by limitations in the acquired data that restrict how well an elastic inversion can currently reconstruct these models? Or are there other reasons why one approach might be preferable over the other, and over conventional migration?
Hence, this workshop encourages a lively discussion of this apparent quandary through examples of both the existing (migration-based) and new (FWI-based) approaches, as well as critical QC of these processes. The workshop further encourages exploration of how to use and integrate these FWI products into our quantitative interpretation workflows, and how to adapt our conventional inversion workflows to accommodate the perceived benefits of the pre-stack FWI-AVA and/or elastic FWI over conventional migrations.
Sub-Topics that will be covered in the workshop:
- Comparison of acoustic-based pre-stack FWI approaches with elastic FWI solutions.
- Discussion of migration and FWI approaches for pre-stack amplitude analysis.
- Advancing quantitative interpretation and integration with pre-stack FWI applications.
Participant Profile
Researchers, practitioners, students and decision makers interested in better understanding the value and challenges of extracting amplitude information from FWI, migration and other wave-equation methods.
Workshop Programme
Coming Soon!
| Time | Activity |
|---|---|
| Part 1: Overview (M. Vardy and M. Vanneste) | |
| 08:55 | Introduction |
| 09:00 | Advances in Ground Models for Offshore Wind - L. Arlott (RWE) |
| 09:30 | Ground Modelling for Design, Installation and Operation of Electrical Cables in Offshore Wind - N. Dyer (Cathie Associates) |
| 10:00 | Coffee break |
| Part 2: Data Interpretation For Ground Modelling (A. Barwise and N. Dyer). | |
| 10:30 | Revealing Foundation Hazards and Ancient Glacial Environments using 3DUHRS - R. Bell (Imperial College) |
| 10:50 | Advances in AI for Geohazard Interpretation - K. St Clair (BP) |
| 11:10 | Squaring the circle of resolution, efficiency and interpretation ambiguity for buried boulder hazard assessment - A. McKay (PGS) |
| 11:30 | Predicting CPT Sampling Challenges using Geophysical Data C. Clay (SAND Geophysics) |
| 11:50 | Lunch break |
| Part 3: Cutting-Edge and Future Techniques (G. Wood and E. Cauquil). | |
| 13:10 | Using time series analysis to support offshore site investigation planning and the adoption of synthetic CPTs - J. Charles (University of Southampton) |
| 13:30 | On the Benefits of Shear Wave Data for Offshore Wind Developments - J.-R. Dujardin (NGI) |
| 13:50 | Soil Characterisation for Windfarms with Oil and Gas Reservoir Characterisation Tools - L. Barens (TotalEnergies) |
| 14:10 | Relating Synthetic CPTs to Foundation Design - R. Klinkvort (NGI) |
| Part 4: Panel Discussion. | |
| 14:30 | Open floor discussion with 4 industry experts (TBC) |
| 15:30 | End of workshop |
